Electrical apparatus



Sept. BENIQFF ELECTRICAL APPARATUS 7 Filed April 30, 1941 2Sheets-Sheet. 2

I u I IIIIIIIII INVENTOR HUGO Brawl BY was Patented Sept. 10, 1946ELECTRICAL APPARATUS Hugo Benioff, La- Canada, Calif., assignor, by'mesne assignments, to Submarine Signal Company, Boston, Mass, acorporation of Delaware Application April 30, 1941, Serial No. 391,153

l The present invention relates to short wave transmitting apparatus andparticularly to spark transmission of very high frequencyelectromagnetic waves. The present invention further relates to a methodand-apparatus for accurately controlling the time of emission ofelectromagnetic wave trains at ultra-high frequencies in the rangeapproximately of v 300 megacycles'and producing very short signalimpulses for the purposes of directive radiation with the use of aradiating horn ifdesired.

The present invention further is concerned with the production andradiation of increased power at these very high frequencies and to thisend employs a specialtype of high frequency tan-k oscillator in whichincreased power may be developed. This oscillator preferably contains inseries a main spark gapand two auxi1- iary spark gaps although theauxiliary spark gaps may be eliminated in the operation of the system.The power is supplied to this series circuit through the secondary of anair core transformer the primary of which is operated by a condenserdischarge tube controlled or triggered periodically by means of acontrol tube, preferably a thyratron. The circuit formed by thedischarging condenser, the tube and transformer are arranged to havesufficient resistance to provide a highly damped type of oscillation sothat only the initial oscillation will operate the circuit.

Further advantages and features of the present invention will beunderstood from the specification below tak n in connection with thedrawings in which Fig. 1 shows a vertical section through the apparatus;Fig. 2 shows a modified detail of an element shown in Fig. 1 Fig. 3shows a section on the line 33 of Fig. 4; Fig. 4 shows a top View of thedetail shown in Fig. 2; Fig. 5 shows a section on the line 5-5 of Fig.l; and Fig. 6 shows a circuit diagram which may be used in connectionwith any of thefigures.

in Fig. 1 there is provided an airtight chamber l within a casing 2which may be made of metal or conducting material with a valve 3 at oneside through which air or gas may be pumped under pressure. The top ofthe casing is covered '4 Claims. (Cl. 25017) by a plate 4 whichhermetically seals the casing "time of spark discharge.

casing is a supporting bracket 8 containing the spark-oscillating device9 of the general type described in my copending application Serial No.362,434, filed October 23, 1940, but differing in certain respects whichwill be described later. Two. high-tension insulators [0 and [I aremounted in the base I of the chamber I and provide a supportrespectively for the conductors l2 and I3 in series with each of whichare resistors l4 and I5 and the spark gaps l6 and I1, respectively. Thespark gaps I6 and I1 are opposed to the terminals l8 and I9respectively, which, in turn, connect to the metallic cones 20 and 2!tapering to center points 22 and. 23 which are preferably of some hardmetal such as tungsten. The cones 20 and 2 I are supported by micainsulating plates 24 and 25, respectively, which are mounted at the endsof the element 26 which is cylindrical in its outer shape with theinterior hollowed out to the shape of cones sothat the inner surfacesHand 28 are respectively spaced away from the sides of the cones 20 and2|.

The element 26 at its end has flat sections 29 and 3|] against which themica insulating sheets 24 and 25 are held fast. In back of the casing 2in a second chamber 3|, which need not be air tight, is mounted an aircore transformer 32 whose secondary 33 supplies power to the spark tankcircuit and the primary 34 of i which is connected through theconcentric cable 35 to the power supply source which is more completelydescribed in Fig. 6.

In Fig. 6 the air core transformer 32 with the output secondary 33 andthe input primary 34 may be operated and controlled through a circuit inwhich a thyratron tube 41 initiates the discharge through one of thecondensers C1, C2 or C3 through the proper connection of the switch 44.The condensers C1, C2 and C3 are charged by the direct current highpotential source indicated at 46 through one of the resistances R1 to R5depending upon the position of the switch 45. The condensers aredischarged by means of the thyratron tube 41 the grid of which is biasedby the battery 48 in series with a triggering oscillating sourc 49 whichmay be sinusoidal peaked or saw-toothed in shape and may periodicallyfurnish a sullicient potential to the grid to initiate the discharge ofthe condenser circuit between the cathode and anode of the thyratrontube 41, and thus control the When the thyratron 47 breaks down, theresistance R1 to R5 connected in circuit is substantially shorted, butthe damping of the discharge is controlled by the adjust abl resistance43 to provide one major oscillation with only minor subsequent onesinsufficient to cause a breakdown of the oscillator spark circuit.

In the operation of the system shown in Fig. 1, the tank circuit ischarged across from the spark point Hi to the spark point I! which, inturn, breaks down with the breakdown of the sparking points 22 and 23,thus causing an oscillation of electrical energy in the cones 29 and 2|and a radiation in the direction of the horn 50.

In the modification shown in Figs. 2, 3 and 4 an arrangement showingsubstantially half of the member 9 is illustrated. In this case the central conical element 5| is supported by the conical shell 52 by means ofthe mica disc 53 through the screws 54 holding the cone 5| to the micaand screw 55 holding the mica disc to the external cone 52. A uniformspace 56 is provided between the elements 5| and 52. At the apex of thecone 5| there is attached a tungsten other sparking point 51 which isopposed by the point 58 adjustably positioned by means of the screw 59on which the spark 58 is mounted. The screw 59 threads through thecylindrical end 60 of the element 52 andpermits an adjustment by meansof the screw 59 of the spark gap along the center axis of the cone. AWindow 6| is provided so that the adjustment of the gap may be properlyviewed. Mounted in the cone element 5| may be the antenna 62 which maybe of such a dimension as to provide the desired resonance in tuning ofthe system. This unit may be substituted for the unit 9 in Fig. 1.

Having now described my invention, I claim:

1. An ultra-high frequency electromagnetic spark oscillator comprisingtwo opposed sparking points, a conical conductive member supporting oneof said points and a conical conductor shell surrounding and having asurface parallel to and spaced from said conical member supporting theother of said points, said points being closer together than the shelland the conductive member whereby the spark takes place between thesparking points and an insulating disc supporting said conical member tosaid shell.

2. An ultra-high frequency electromagnetic spark oscillator comprisingtwo opposed sparking points, a conical conductive member supporting oneof said points and a conductor shell surrounding and spaced from saidconical member supporting the other of said points and an insulatingdisc supporting said conical member to said shell and electromagneticradiating means extending from said conical member.

3. An ultra-high frequency electromagnetic spark oscillator comprisingtwo opposed sparking points, a conical conductive member supporting oneof said points and a conical conductor shell surrounding and having asurface parallel to and spaced from said conical member supporting theother of said points, said points being closer together than the shelland the conductive member whereby the spark takes place between thesparking points and an insulating disc supporting said conical-member tosaid shell and means for adjusting one of said sparking points along thecentral axis of the cone.

4. An ultra-high frequency electromagnetic spark oscillator comprisingtwo opposedsparking points, a conical conductive member supporting oneof said points and a conductor shell surrounding and spaced from saidconical member supporting the other of said points and an insulatingdisc supporting said conical member to said shell and electromagneticradiating means extending from said conical member and means foradjusting one of said sparking points along the central axis of thecone.

HUGO BENIOFF.

